The invention relates to a machine tool having a motor-driven machine spindle which can be rotated about a spindle axis and has an end-side tool holder, and having an inserted tool which is arranged exchangeably on the machine spindle and has a coupling element which is compatible with the tool holder of the machine spindle and has a rear face which points to the machine spindle, having an end face which comprises the tool holder and lies opposite the rear face of the coupling element, and having at least one co-rotating galvanic contact point for electric current or data transmission, which contact point is arranged between the machine spindle and the inserted tool and has a spindle-side contact element which is arranged on the end face of the tool holder and a tool-side contact element which is arranged on the rear face of the coupling element.
Machine tools of this type are known. Here, there is an electric line in the machine spindle through which an inserted tool which is received on the machine spindle can be supplied with electric energy. The inserted tool is received with a coupling element in a tool holder on the machine spindle. The tool holder of the machine spindle comprises a planar face. The coupling element of the inserted tool which is received on the machine spindle bears with a planar annular face against the tool holder of the machine spindle. The planar face and the planar annular face can be pressed against one another by means of a coupling mechanism. Planar contact is produced as a result. In each case, one electric line contact is provided on the planar face of the machine spindle and on the planar annular face of the tool holder. When the inserted tool is connected to the machine spindle, these contacts are pressed against one another on account of spring force. The electric line in the machine spindle is then connected to a consumer in the inserted tool.